This invention relates to methods of and apparatus for forming metal containers or the like, utilizing internal fluid pressure to expand a hollow metal preform or workpiece against a die cavity. In an important specific aspect, the invention is directed to methods of and apparatus for forming aluminum or other metal containers having a contoured shape, e.g. such as a bottle shape with asymmetrical features.
Metal cans are well known and widely used for beverages. Present day beverage can bodies, whether one-piece “drawn and ironed” bodies, or bodies open at both ends (with a separate closure member at the bottom as well as at the top), generally have simple upright cylindrical side walls. It is sometimes desired, for reasons of aesthetics, consumer appeal and/or product identification, to impart a different and more complex shape to the side wall and/or bottom of a metal beverage container, and in particular, to provide a metal container with the shape of a bottle rather than an ordinary cylindrical can shape. Conventional can-producing operations, however, do not achieve such configurations.
For these and other purposes, it would be advantageous to provide convenient and effective methods of forming workpieces into bottle shapes or other complex shapes. Moreover, it would be useful to provide such procedures capable of forming contoured container shapes that are not radially symmetrical, to enhance the variety of designs obtainable.